Type Aliases vs Interfaces in TypeScript

What are the main differences between type aliases and interfaces in TypeScript?

Type aliases and interfaces are both used to define types in TypeScript, but they have some key differences. Type aliases can represent any valid type, including primitives, unions, and tuples, while interfaces are specifically for object types and can be extended or implemented.

Can you give me an example of when to use a type alias instead of an interface?

Sure! Use a type alias when you need to define a union type. For example, type StringOrNumber = string | number; is a type alias that allows a variable to be either a string or a number.

Are there any performance differences between using type aliases and interfaces?

Generally, there are no significant performance differences between type aliases and interfaces. The choice between them is more about code organization and readability.

Can interfaces extend multiple other interfaces?

Yes, interfaces can extend multiple other interfaces, allowing you to combine their properties. For example: interface A { x: number; } interface B { y: string; } interface C extends A, B { z: boolean; }.